text: Unlike the majority of ACE inhibitors, captopril is not administered as a prodrug (the only other being lisinopril). About 70% of orally administered captopril is absorbed. Bioavailability is reduced by presence of food in stomach. It is partly metabolised and partly excreted unchanged in urine. Captopril also has a relatively poor pharmacokinetic profile. The short half-life necessitates dosing two or three times per day, which may reduce patient compliance. Captopril has a short half-life of 2–3 hours and a duration of action of 12–24 hours.